The semiconductor integrated circuit industry has experienced exponential growth. Technological progresses have produced smaller and more complex circuits than the previous generation. In the evolution of the integrated circuit industry, functional density generally increased while geometry size decreased. This scaling down process increases production efficiency and reduces manufacturing costs. Such scaling down also increases the complexity of integrated circuit processing and manufacturing. For these advances to be realized, similar developments in integrated circuit processing and manufacturing are needed.
A common requirement in current advanced integrated circuit processing is a wafer cleaning process. Particles or films are left on the surface of a wafer for subsequent fabrication operations; however, the unwanted residual materials may cause, among other things, defects such as scratches on the wafer surface and inappropriate interactions between metalization features. Usually, the unwanted residual materials are substances such as metals, environmental gas components, and moisture. In some cases, such defects on the wafer surface may cause reduced yield or breakage of integrated circuit devices. In order to avoid the undue costs for discarding wafer having inoperable devices, it is necessary to clean the wafer adequately yet efficiently after fabrication operations that may leave unwanted residue on the surface of the wafer.
During a cleaning process of the wafer, the unwanted residual materials aggregated into particles near an edge of the wafer are difficult to remove. Standard cleaning techniques fail to sufficiently clean and remove these particles from the wafer. The unwanted particles on the edge of the wafer may flake off to a work piece region of the wafer, causing the reduced device yield or destructing the integrity of the integrated circuits.